Functional matching and renormalization group equations at two-loop order Fuentes Martín, Javier Palavric, Ajdin Thomsen, Anders Eller We present a systematic method for determining the two-loop effective Lagrangian resulting from integrating out a set of heavy particles in an ultraviolet scalar theory. We prove that the matching coefficients are entirely determined from the (double-)hard region of the loop integrals and present a master formula for matching, applicable to both diagrammatic and functional approaches. We further employ functional methods to determine compact expressions for the effective Lagrangian that do not rely on any previous knowledge of its structure or symmetries. The same methods are also applicable to the computation of renormalization group equations. We demonstrate the application of the functional approach by computing the two-loop matching coefficients and renormalization group equations in a scalar toy model. 2024-05-28T08:17:18Z 2024-05-28T08:17:18Z 2024-03-05 journal article Fuentes-Martín, Javier, Ajdin Palavrić, and Anders Eller Thomsen. Functional matching and renormalization group equations at two-loop order. Phys. Lett. B 851 (2024) 138557 [10.1016/j.physletb.2024.138557] https://hdl.handle.net/10481/92137 10.1016/j.physletb.2024.138557 eng info:eu-repo/grantAgreement/EC/NextGenerationEU/IJC2020-043549-I http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional Elsevier